Electronic musical instrument having tone start pitch fluctuation arrangement

ABSTRACT

An electronic musical instrument including tone generators for generating tone signals each having predetermined tone pitches constituting a musical scale and tone keyers for respectively keying the tone signals, is further provided with a circuit arrangement for fluctuating the pitch of the tone at the start of the tone. The arrangement comprises a detector for detecting the start of the tone signal being played and a pulse generator producing a pulse signal upon receipt of the detected signal and controlling the tone generators to fluctuate the pitches thereof at the start of the tone signals. This simulates the sound of natural musical instruments very closely.

United States Patent Nakada Mar. 27, 1973 ELECTRONIC MUSICAL HAVING TONESTART PITCH FLUCTUATION ARRANGEMENT Akira Nakada, Hamamatsu-shi, JapanNippon Gakki Seizo Kabushiki Kaisha, Hamamatsu-shi, Shizuokaken, JapanFiled: Dec. 23, 1971 Appl. No.: 211,602

[75] Inventor:

[73] Assignee:

Foreign Application Priority Data Dec. 26, 1970 Japan ..45/1 1.9034

US. Cl ..84/1.24, 84/125 Int. Cl. ..Gl 0h 1/04 Field of Search..s4/1.o1, 1.24-1.26,

References Cited UNITED STATES PATENTS 12/1954 Kent ..84/l.26 x

MASTER FREQUENCY OSCILLATORS DIVIDERS TON KEYERS PULSE GENERATORRECTIFIER TONE COLORING FILT Primary Examiner-Richard B. WilkinsonAssistant Examiner-U. Weldon Attorney-Robert D. Flynn et al.

[ ABSTRACT tone signals. This simulates the sound of natural musicalinstruments very closely.

5 Claims, 4 Drawing Figures r22 23 AMPLIFlER I ERS AMPLITUDE LIMITERPATENIEDmznms SHEET 2 OF 3 F I G. 2

TO MASTER TR1 OSCILLATORS FROM RECT!FlER TONE OUTPUT TONE OUTPUT 151 1 1+8 r A -TR3 l o E8935 SUCCEEDING GENERATOR STAGE TONE START PITCHFLUCTUATION ARRANGEMENT BACKGROUND or THE INVENTION The presentinvention relates to an electronic musical instrument, and moreparticularly to an electronic musical instrument wherein the tonepitches are shortly fluctuated at the start of the tone signals.

Conventional musical instruments such as stringed, wind and percussioninstruments generally produce sounds having such pitch or frequency thatare not maintained at any predetermined pitch from the start to thedecaying erid of sounds, but are fluctuated higher or lower (usually, byabout 20 to 30 cents) for a short time mainly at the start of the soundand then comes to its predetermined pitch during the sustaining ordecaying period.

Electronic musical instruments, such as an electronic organ, are sodesigned as to generate tone signals having individually predeterminedpitches by means of tone generators, and generally include a plurality(mostly, l2 constituting the highest one octave) of master oscillatorsand multistaged frequency dividers cascade connected in turn to each ofthe oscillators.

Accordingly, prior art electronic musical instruments have thedisadvantages that they generate only monotonous tone signals each beingmaintained at its predetermined pitch from the rise to the decay thereofand widely departing from the sense of sounding of natural musicalinstruments.

Therefore, the principal object of the invention is to provide anelectronic musical instrument having sounding characteristics closelyresembling those of the sounds of natural musical instruments.

SUMMARY OF THE INVENTION According to the present invention, there isprovided an electronic musical instrument comprising tone generatorsgenerating tone signals, tone keyers connected to the tone generatorsand keying the tone signals, a tone signal passage or coupling meansconnected to the torie keyers and conducting the keyed tone signal, adetector connected to the tone signal passage and detecting a start ofthe keyed tone signal, and a pulse generator connected to the detectorfor producing a pulse signal upon detection of the tone signal start andto the tone generators for fluctuating the frequencies of the generatingtone signals.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block diagram ofan electronic musical instrument according to an embodiment of theinvention;

FIG. 2 shows a concrete circuit arrangement of the pulse generator ofFIG. 1;

FIG. 3 illustrates a concrete circuit diagram of a part of the masteroscillators and frequency dividers of FIG. 1; and

FIG. 4 is a schematic block diagram of an electronic musical instrumentaccording another embodiment of the invention.

PREFERRED EMBODIMENTS OF THE INVENTION Referring now to FIG. 1, anelectronic musical instrument according to an preferred embodiment ofthe invention is shown by numeral 10 as a whole.

The instrument 10 comprises a keyboard 12 having a plurality of keys111, 112 lln juxtaposed in the order of musical notes; tone keyers 13having a plurality of key switches provided for the respective keys 11 1to lln on the keyboard 12 to be actuated interlockingly with thecorresponding keys upon their selective depression; and tone generators14 generating tone signals having pitches predetermined for theindividual musical notes and, only upon depression of the correspondingkeys, producing tone signals therefrom. The tone generators 14 include aplurality (generally 12) of master oscillators 15 for generatingindividually the tone signals in the highest octave and a plurality ofmultistaged frequency dividers 16 cascade connected in turn to each ofthe oscillators 15. The line 24 and the succeeding circuits 20, 21 and22 constitute a tone signal passage or tone signal coupling means of theinstrument.

With an electronic musical instrument arranged as described above, thereis generated only monotonous tone signals each being maintained at apredetermined pitch from the start (rise) to the end (decay) thereof andwidely departing from the sounding characteristics of natural musicalinstruments as well known in the art and as abovementioned. I

Therefore, the instrument 10 of this invention has the followingarrangement for tone start pitch fluctuation, in order to obtain tonesignals having sounding characteristics as closely resembling those ofthe natural musical instruments as possible.

There is first supplied each tone signal generated by the tonegenerators l4 and derived through the tone.

keyers 13 and the line 24 to an amplitude limiter 17 consisting of, forexample, a conventional saturation amplifier, and followed by arectifier 18. The rectified signal from the rectifier 18 is thensupplied as a trigger signal to a pulse generator 19 constituted by,e.g., a one-shot multivibrator 191 including two emitter groundedtransistors TR, and TR as shown in FIG. 2. The pulse generator 19 is soarranged as to be triggered by the trigger signal thus obtained and togenerate a pulse signal e having a relatively short duration time (e.g.,about 20 ms) at the very moment of the starting portion of the keyedtone signal. This pulse width is determined by the values of a capacitorC and a resistor R. I

Thus, the pulse signal produced by the pulse generator 19 is supplied asa frequency changing signal to the tone generator 15. The resultantfrequency changed tone signals drawn out through the keyers 13 areconducted through the line 24, tone coloring filters 20, a volumecontrol 21 and an amplifier 22 to be reproduced from a loud-speaker 23.

FIG. 3 shows a concrete circuit diagram of the one master oscillator 15and the one frequency divider 16, I the former being formed of a Hartleytype oscillator 151 including a transistor TR followed by a clipperincluding a transistor TR,,, and the latter consisting of a bistablemultivibrator 161 including two emitter grounded transistor TR and TR;cascade connected to the transistor TR respectively. In this case, thepulse signal generated by the pulse generator 19 is conducted to thebase of transistor TR to fluctuate its oscillation frequency.

With the instrument of this invention arranged as described above, it isapparent that there are easily obtained tone signals having naturalsounding characteristics closely simulating sounds of various naturalmusical instruments.

FIG. 4 is a block diagram of an electronic musical instrument 101according to another embodiment of the invention. a

In this embodiment, the output signal of the pulse generator 19 is notdesigned to be used as a direct frequency fluctuating signal, but to beused for gating the later described noise signal, thereby producing apulsive noise signal. That is, white noise signals generated by a whitenoise signal source 31 are supplied through a filter 32 devised to passonly a frequency component of less than about 1,000 I-Iz (preferablysufficiently lower than the oscillator frequency) therethrough to a gatecircuit 33 and gated by the output pulse signal from the pulse generator19. Thereby, the oscillation frequency of each tone signal generated bythe tone generator 14 is fluctuated by a pulsive noise signal e thusobtained.

In FIG. 4, a numeral 34 represents switch circuits turned on or off by aplayer for the purpose of producing therethrough tone signals having aparticular musical effect such as a sustain effect, if required.

What is claimed is:

1. An electronic musical instrument comprising:

tone generators generating tone signals;

tone keyers connected to said tone generators and keying said tonesignals;

a tone signal coupling means connected to said tone keyers and couplingthe keyed tone signal to an output;

plitude limiter and a rectifier coupled to the output of said amplitudelimiter.

3. An electronic musical instrument according to claim 1 wherein saidtone generators include master oscillators generating tone signals ofthe notes in the highest octave and multistage frequency dividerscascade connected to each of said master oscillators for generating tonesignals of the notes in the subsequent octaves.

4. An electronic musical instrument according to claim 1 wherein saidpulse generator includes a one shot multivibrator.

5. An electronic musical instrument according to claim 1 which furthercomprises a white noise source generating white noise si als, and

a filter connected to e output of said white noise source, andsaid meanscoupling said pulse signal to said tone generators comprises a gatecircuit having an input thereof coupled to said filter and the'outputthereof coupled to said tone generators, said pulse generator beingconnected to another input of said gate circuit and controlling saidgate circuit to gate the white noise signal to said tone generators thegated white noise signal fluctuating the frequencies of said tonesignals.

* I I! I

1. An electronic musical instrument comprising: tone generatorsgenerating tone signals; tone keyers connected to said tone generatorsand keying said tone signals; a tone signal coupling means connected tosaid tone keyers and coupling the keyed tone signal to an output; adetector means connected to said tone signal coupling means fordetecting a start of said keyed tone signal; a pulse generator connectedto the output of said detector means for producing a pulse signal upondetection of the start of said keyed tone signal by said detector means;and means for coupling said pulse signal to said tone generators forfluctuating the frequencies of said tone signals.
 2. An electronicmusical instrument according to claim 1 wherein said detector meanscomprises an amplitude limiter and a rectifier coupled to the output ofsaid amplitude limiter.
 3. An electronic musical instrument according toclaim 1 wherein said tone generators include master oscillatorsgenerating tone signals of the notes in the highest octave andmultistage frequency dividers cascade connected to each of said masteroscillators for generating tone signals of the notes in the subsequentoctaves.
 4. An electronic musical instrument according to claim 1wherein said pulse generator includes a one shot multivibrator.
 5. Anelectronic musical instrument according to claim 1 which furthercomprises a white noise source generating white noise signals, and afilter connected to the output of said white noise source, and saidmeans coupling said pulse signal to said tone generators comprises agate circuit having an input thereof coupled to said filter and theoutput thereof coupled to said tone generators, said pulse generatorbeing connected to another input of said gate circuit and controllingsaid gate circuit to gate the white noise signal to said tone generatorsthe gated white noise signal fluctuating the frequencies of said tonesignals.